hg: shenandoah/jdk: Improve C2 barrier filtering: heap-stable check should test for HAS_FORWARDED only

[ashipile at redhat.com]

Changeset: 78d582904313
Author:    shade
Date:      2018-07-20 15:26 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/78d582904313

Improve C2 barrier filtering: heap-stable check should test for HAS_FORWARDED only

! src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp
! src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp